This invention relates generally to protection of electronic circuits and more particularly concerns devices for preventing foreign conductive substances from passing over the electrical components of machines while power is connected to those components.
The annual cost of repairing damage to personal and business equipment such as typewriters, computers, copiers and the like resulting from spilled liquids, paper clips, staples, coins and other conductive materials contacting electronic components while they are operating is considerable. In addition, losses due to natural causes or vandalism impacting the electronic components of automatic teller machines, telephones, change machines, generators, motors and similar equipment are significant.
In one particular example, the salting of vending machines with any of a variety of conductive substances for the purpose of causing the internal electrical components of the machines to function without compliance with those protocols established for appropriate access is becoming an increasingly frequent and expensive problem. Salting not only results in the obvious losses from the avoidance of the protocol, but also in damage to the electrical components contacted by the substances with ensuing down time and repair losses and, at times, even in fire or safety hazards.
While known protection devices do reduce the losses incurred as the result of protocol avoidance, natural or otherwise, they do not terminate power to all of the internal components of the machine quickly enough to minimize equipment damage. The known devices do not detect the substance prior to contact with the machine circuitry and, therefore, the substance penetrates to at least some of the electrical components prior to detection. Location of protection devices at the point of entry of the foreign substance has heretofore been impractical because of the relative insensitivity of the substance sensors. For example, salting is often accomplished by infiltrating the point of entry with a saline solution. While sensors are generally sensitive enough to distinguish the presence of one drop of saline solution contacted, present anti-salting devices are unable to distinguish between a drop of saline solution and a drop of non-saline water. Consequently, such devices cannot be universally used. In outdoor conditions, an inconsequential drop of rainwater could trigger the sensors. Even in indoor conditions such as a pool area, a laundromat or any other water-accessible location, wet hands or splashing water could cause the mechanism to operate and unnecessarily shut down the machine.
It is therefore an object of this invention to provide a protection device which detects a foreign substance as close as possible to its point of entry into any of a variety of machines including, but not limited to, automatic teller machines, game machines, vending machines, office machines and the like. Another object of this invention is to provide a protection device usable with a wide variety of sensors so that different substances can be detected. It is also an object of this invention to provide a protection device in which multiple sensors may be used to monitor a multiplicity of entry points into the electrical equipment. Furthermore, it is an object of this invention to provide a protection device which initiates power interruption procedures upon detection of a foreign substance at a point of entry. Another object of this invention is to provide a protection device which generates a signal usable to initiate operation of one or more of a variety of circuits upon detection of a foreign substance at its point of entry. And it is an object of this invention to provide a protection device which will trigger an alarm upon infiltration by a foreign substance into a port of entry into the machine. In the event an alarm is incorporated in the device, it is further an object of this invention to provide a protection device in which a timer controls the activation and deactivation of the alarm.